import math


def prime_number(n):
    num_list= []
    for num in range(1,n+1):
        prime = True
        #1、质数需要大于1
        if num <=1:
            continue
        # 2、质数不能被其他数整除
        # print(int(math.sqrt(num)))
        for i in range(2,int(math.sqrt(num))+1):
            if num % i == 0:
                prime = False
                break
            else:
                prime = True
        if prime:
            num_list.append(num)
    return num_list
def list_hebing(list_data):
    list_data = len(list_data)
    print(list_data)
    # print(len(list_data))
    # mid = len(list_data)/2
    # left = list_data[:mid]
    # right = list_data[mid:]
    # print(left,right)
if __name__ =="__main__":
    # print(prime_number(1000))
    list_data = [5,2,9,4,8,3,1,7,10,11]
    list_hebing(list_data)